1. Technical Field
The present invention relates to an electro-optical device, such as a liquid crystal device manufactured by a rubbing process for rubbing an alignment film, to a method of manufacturing an electro-optical device, and to an electronic apparatus having the liquid crystal device.
2. Related Art
In general, an electro-optical device has a structure in which liquid crystal is inserted between two substrates each of which is composed of a glass substrate, a quartz substrate or the like. In the electro-optical device, switching elements, such as thin film transistors (hereinafter, simply referred to as TFTs), are disposed in a matrix on one substrate, and a counter electrode is disposed on the other substrate. Image display can be performed by varying an optical characteristic of a liquid crystal layer interposed between the two substrates in accordance with an image signal.
A TFT substrate on which the TFTs are disposed and a counter substrate on which the counter electrode is disposed are formed so as to be separated from each other, and are bonded to each other with high precision after alignment films, which are formed on surfaces of the TFT substrate and the counter substrate coming into contact with the liquid crystal layer, are subjected to a rubbing process. A groove is generally formed in a region of the TFT substrate excluding an image display region in order that an external terminal electrode laminated on the TFT substrate or an electrode for electrically connecting the TFT substrate and the counter substrate is exposed to the outside.
In such an electro-optical device, various technologies for improving a display quality have been developed. For example, a technology has been disclosed for improving the display quality using the above-mentioned groove (for example, see JP-A-10-232399).
However, if an uneven shape, such as a groove, exists on the TFT substrate, since minute alignment irregularities may occur on the alignment film, a display quality may be deteriorated due to the alignment irregularities. Accordingly, various technologies have been examined in order to resolve the above-mentioned problems, but cannot resolve the problems. For example, when an edge of an opening formed on the surface of the TFT substrate has a portion extending in parallel to the rubbing direction, fabric disorder may occur in a cloth material of a rubbing roller using the portion extending in parallel to the rubbing direction as a boundary. In particular, when the rubbing process is performed using the rubbing roller where the fabric disorder occurs, striped alignment irregularities may occur on the alignment film. The inventors have concluded that the alignment irregularities occur due to the fabric disorder occurring in the cloth material of the rubbing roller, and the alignment irregularities lower the display quality of the liquid crystal device or the like.